1. Field of the Invention
Aspects of this invention relate generally to automotive parts, and more particularly to an improved automotive engine cooling pipe.
2. Description of Related Art
The subject of this patent application is an improved automotive engine cooling pipe particularly configured for installation in engines wherein such a cooling pipe is originally factory-installed. Typically such cooling pipes must be installed axially or in a lengthwise direction from the front of the engine, making installation extremely labor-intensive, as compared to being able to somehow install such pipes laterally from above. The present invention meets this need and solves other related problems as described in more detail herein.
By way of background, and in more detail regarding the problem addressed by the automotive engine cooling pipe apparatus and method of use of the present invention, particularly in the “N62” engine manufactured by BMW and installed primarily in that automaker's “7 series” sedans from 2002 to present, as shown in Table 1 below, the engine is configured with an approximately 17″ long×1⅜″ diameter extruded aluminum cooling pipe that traverses the engine block from front to back and seals at each end for the purpose of delivering coolant therethrough from the water pump to the rest of the engine. The factory-installed cooling pipe or transfer tube as well as any such replacement part (BMW part #11-14-1-339-975) is again a single extrusion tube that also has a pre-installed gasket-type seal at one end configured to seat and seal within the opening in the front end of the engine block into which the cooling pipe is installed, substantially between the engine block and the timing cover. This gasket is essentially bonded to the pipe outside surface as through a vulcanization process or the like. Over time, whether through failure to regularly replace the coolant or simply through normal “wear and tear,” the seal fails as its material just breaks down and corrosion underneath the seal around the pipe propagates and compromises the seal at that surface. Eventually, coolant is able to get by the factory-installed seal about the front end of the cooling pipe and will leak into the back area of the engine timing cover and out of a small ⅓″ hole in front of the timing cover. In order to repair this leak, the cooling pipe must be removed and replaced, requiring disassembly of much of the engine, including the intake manifold, water pump, valley pan, valve covers, timing covers, and timing assembly, the entire job then typically requiring on the order of 60-70 man-hours and so being quite expensive. In a bit more detail, due to the relative “net fit” of the cooling pipe within the engine block and it not having sufficient rearward axial movement to gain access to the failed front seal without removing the pipe, the only way to get to that seal is to either access the pipe from the front of the engine, requiring removal of the valve and timing covers and timing assembly, or to cut the pipe in half and remove it in two parts. While this second alternative saves the labor of disassembling much of the front of the engine, that must still be done anyway in order to install the new factory cooling pipe and seal. Accordingly, using the BMW cooling pipe or transfer tube to repair this coolant leak necessitates the time-consuming and expensive removal and reassembly of much of the front of the engine.
TABLE 12002-2005:BMW 745I & IL (E65 & E66)2006-2008:BMW 750I & IL (E65 & E66)2004-2006:BMW X5 4.4i/4.8is (E53)2007-2010:BMW X5 4.8i (E70)2004-2005:BMW 545i (E60)2006-2010:BMW 550i (E60 & E61)2004-2005:BMW 645Ci (E63 & E64)2006-2010:BMW 650i (E63 & E64)2002-2005:Range Rover
The following art defines the present state of this field:
U.S. Pat. No. 3,699,934 to Gaipo et al. is directed to an extensible lubricant-return tube, for enclosing a pushrod in an internal combustion engine, having gaskets at the opposite ends of the tube and comprising an outer sleeve and an inner insert. The outer sleeve is internally smooth and the inner insert is externally threaded in the area where it telescopes into the sleeve. A pair of internally threaded locking torroids disposed on the inner insert serve to adjust and lock the sleeve and insert to the required length.
U.S. Pat. No. 3,907,334 to Schera, Jr. is directed to a telescopic conduit nipple having a cylindrical outer tubular member with a linear slot therein parallel the axis thereof. One end of the outer member having an integral outer flange terminates in a male thread of predetermined pitch and length. An inner cylindrical tubular member slidably fitted for predetermined coaxial linear adjustment within the outer member with the outer end thereof having a coaxial outer flange terminates in a male thread of predetermined pitch and length includes screw means through the slot and threaded into said inner member for locking the adjusted length of the nipple.
U.S. Pat. No. 3,994,516 Fredd is directed to a threaded interconnect structure incorporating respective matching internal and external threaded portions of members to be threadedly interconnected, with the thread geometry defining a profile having contiguous straight-thread and tapered-thread sections. Sealing integrity and make-up length and sealing predictability of the threaded interconnection are improved over standard tapered-thread joints. Tapered sections have a taper in excess of standard taper-threaded profiles and comprise comparatively fewer threads, with the sealing action in the tapered section being mechanically aided by the straight-thread sections during make-up of the joint, and thereafter mechanically reinforced by the straight-thread sections. A tool chaser of new and novel design permits cutting straight-tapered profile transitions with maintenance of pitch and thread matching.
U.S. Pat. No. 4,012,061 to Olson is directed to a dual conduit drill stem member that includes a pipe having two piece tube therewithin affixed to the pipe at outer ends and inner ends coupled by a composite elastomeric sleeve and telescopic metal coupling, adjacent members being connected by threaded tool joints on pipe ends and compression sealed telescopic joints on tube outer ends.
U.S. Pat. No. 5,823,578 to Chiou is directed to an extensible metallic tube structure that has a big hollow tube, an engaging head, a small hollow tube, a locating column, an O-shaped ring, a washer, a C-shaped fixing device, and a controlling sleeve. The big hollow tube has an inwardly indented groove at the upper periphery engaged with the engaging head at one end. The small hollow tube fixed with locating column is led through the other end of the big hollow tube. In sequence, the O-shaped ring, the washer, the C-shaped fixing device and the controlling sleeve are led through the upper end of the small hollow tube. The controlling sleeve is screwed up to the engaging head via threads. An inner protruding flange defining the other side of the inwardly indented groove of the big hollow tube will prevent the small hollow tube from coming off when it is extended to the extreme. And via the controlling sleeve generating a pushing force when screwed up to the engaging head, the C-shaped fixing device will clamp tightly against the small hollow tube to locate the small hollow tube into position when the tube is being adjusted. In addition, the C-shaped fixing means will abut closely against the washer and the washer tightly against the O-shaped ring to provide a secure connection of the big and small hollow tubes, so that the water will not flow downwards or leak outwardly at the joint when the big and small hollow tubes are adjusted and uplifted to supply water for cleaning purpose.
The prior art described above teaches an extensible lubricant-return tube for internal combustion engines, a linear adjustable telescopic nipple, a telescoping pipe coupling with improved pressure seal connection threads, a dual conduit drill stem member, and an extensible metallic tube structure, but does not teach an automotive engine cooling pipe apparatus for fluid-conducting installation with an engine block of an engine laterally or “from above” as facilitated by a telescoping, tube-in-tube construction of the apparatus. Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.